I. Field
The following description relates generally to wireless communications, and, amongst other things, to flexible communication schemes for wireless communications systems.
II. Background
In the not too distant past mobile communication devices in general, and mobile telephones in particular, were luxury items only affordable to those with substantial income. Further, these mobile telephones were significant in size, rendering them inconvenient for extended portability. For example, in contrast to today's mobile telephones (and other mobile communication devices), mobile telephones of the recent past could not be placed into a user's pocket or handbag without causing extreme discomfort. In addition to deficiencies associated with mobile telephones, wireless communications networks that provided services for such telephones were unreliable, covered insufficient geographical areas, were associated with inadequate bandwidth, and were associated with various other deficiencies.
In contrast to the above-described mobile telephones, mobile telephones and other devices that utilize wireless networks are now commonplace. Today's mobile telephones are extremely portable and inexpensive. For example, a typical modem mobile telephone can easily be placed in a handbag without a user thereof noticing existence of the telephone. Furthermore, wireless service providers often offer sophisticated mobile telephones at no cost to persons who subscribe to their wireless service. Numerous towers that transmit and/or relay wireless communications have been constructed over the last several years, thus providing wireless coverage to significant portions of the United States (as well as several other countries). Accordingly, millions (if not billions) of individuals own and utilize mobile telephones.
To effectuate continued coverage for mobile stations, access points (base stations, access nodes, etc.) associated with cellular networks are geographically positioned so that as users change location they do not lose services. Thus, mobile stations can be “handed off” from a first base station to a second base station. In other words, a mobile station will be serviced by a first base station while in a geographic region associated with such base station. When the mobile station is transported to a region associated with a second base station, the mobile station will be handed off from the first base station to the second base station. Ideally, the handoff occurs without data loss, loss of service, and the like.
Conventionally, this handoff occurred through a significant amount of messaging between mobile stations and base stations. For instance, as a mobile station was transported toward a base station, various messages were delivered between the mobile station and the base station, as well as between the base station and a base station currently servicing the mobile station. This messaging enables assignment of resources with respect to forward link and reverse link channels to be made between the mobile station and the base stations. To enable a handoff to occur quickly and without loss of a substantial amount of data, a set of base stations can be prepared to provide services to the mobile station. This set of base stations can be updated as the geographic region associated with the mobile station is altered. In more detail, the mobile station can be adapted to monitor for communications or receive communications over a first frequency from a first base station. A second base station can communicate with the mobile station over the same frequency, and the second base station can be added to the set of base stations if particular performance parameters are met. Once the base station is added to the set, it is prepared to service the mobile station once it becomes within a particular geographic range of such base station. The handoff between base stations occurs expediently as well as without loss of any significant amount of data.
Problems arise, however, if base stations associated with disparate technologies or communication protocols are desirably added to the set of base stations, as mobile stations with single receive chains cannot simultaneously communicate between systems and/or over disparate frequencies.